1. Field of the Invention
This invention relates to a wiring board mounting structure for an electrical junction block which is mounted on an automobile or the like.
2. Description of the Related Art
In an automobile, in order to decrease the number of circuit branches of a wire harness, or to accommodate the electrical circuit of a particular control system, electrical junction blocks are mounted.
FIG. 7 is a sectional view showing a conventional wiring board mounting structure of an electrical junction block. In a body 3 of the electrical junction block 1, an electrical circuit for distribution of the electrical power is formed with a bus bar 5. A wiring board (or relay board) 11, on which a fuse 7 and a relay 9 are mounted, is mounted on the body 3. A body side tab 13, which is connected to the bus bar 5, is protruded from the body 3. A board side tab 15, which is connected to the fuse 7 or relay 9, is protruded from the relay board 11. The body 3, the fuse 7, and the relay 9 are electrically connected to one another by spot-welding the body side tab 13 and the board side tab 15, which are adjacent to each other, with the relay board 11 mounted on the body 3. As was described above, in the conventional wiring board mounting structure for an electrical junction block, the tabs are spot-welded to each other. Hence, it is difficult to remove relay board 11 from the body 3, and therefore for instance in the case where the relay 9 is broken, it must be replaced together with the body 3. In this case, other normal (not broken) components must be discarded together with the body. That is, the conventional wiring board mounting structure is not economical.
Furthermore, since a number of pairs of tabs must be spot-welded, the assembling of the conventional wiring board mounting structure is low in work efficiency.